IR Spectroscopy

Hi All,
I am working on a sensitivity model for a short wave IR spectrometer. And I have come up to a few questions that I had never thought of before and that seem really interesting (and I still don't know the answers, so it'd be great if anyone had any insight!)
Well, I need to look at an explosion (say powerful blackbody) and take an IR spectrum to detect few things. Now, the explosion itself is hot and luminous, so how do i detect the spectral lines I want? In short, how do you detect any spectral lines in such an environment?
Thanks for any help...
rp895